The starting point has submachineguns and pump shotguns. Open the door on the upper walkway, and get out into an octagonal chamber. Turn right, and enter either of the two pipes that lead onward, to the upper walkways of the next octagonal chamber.

In the second octagonal chamber, seek the ladder through the walkways that goes down to the bottom. There may be weapons or ammo on the tables across from the bottom of this ladder.

Drop down into the muck at the bottom, and go into the tunnel ahead. Watch out for a possible tank here. This tunnel connects to a square-shaped chamber.

Time for a defense point, at the two-level square-shaped chamber. Climb the ladders up to the upper level. At one corner, activate the switch to begin lowering the floodgates, whose tops will form a bridge across to the other side of the upper walkways. Fight off the incoming waves of infected. When the floodgates are completely lowered, run across them to reach the next tunnel.

Proceed through the passageways, and climb up a fallen set of stairs like a ladder.

Go out through the windows to an exterior area, to a back lot. Enter the train shed. The safe house is the train car on the upper levels of this train shed.